add mw_pole calculation to weinberg_angle class

templates/weinberg_angle.cpp.in

@@ -106,11 +106,17 @@ void CLASSNAME::set_sm_parameters(const Sm_parameters& sm_parameters_)
    sm_parameters = sm_parameters_;
 }
 
+double CLASSNAME::get_mw_pole()
+{
+   return mw_pole;
+}
+
 /**
  * Calculates the DR-bar weak mixing angle \f$\sin\hat{\theta}_W\f$ as
  * defined in Eq. (C.3) from hep-ph/9606211 given the Fermi constant,
  * the Z-boson pole mass and the DR-bar electromagnetic coupling as input
  * and taking the tree-level value of the \f$\hat{\rho}\f$ parameter into account.
+ * Furthermore the W boson pole mass is determined from the final result.
  *
  * The function throws an exception of type NoSinThetaWConvergenceError if the
  * iterative procedure to determine the weak mixing angle does not converge.
@@ -201,6 +207,11 @@ double CLASSNAME::calculate(double sinThetaW_start)
    if (not_converged)
       throw NoSinThetaWConvergenceError(number_of_iterations, sinThetaW_new);
 
+   const double rhohat_ratio_final =
+      1.0 / (1.0 - calculate_delta_rho_hat(sinThetaW_new));
+   mw_pole =
+      Sqrt(Sqr(mz) * rhohat_tree * rhohat_ratio_final * (1 - Sqr(sinThetaW_new)));
+
    return sinThetaW_new;
 }
 

templates/weinberg_angle.hpp.in

@@ -51,6 +51,7 @@ public:
    void disable_dvb_bsm();                   ///< disable bsm wave, vertex and box corrections
    void set_model(const @ModelName@_mass_eigenstates*);  ///< set pointer to investigated model
    void set_sm_parameters(const Sm_parameters&);  ///< set sm_parameters member variable
+   double get_mw_pole();                     ///< get pole mass of W boson
 
    /// calculates and returns the sine of the Weinberg angle
    double calculate(double sinThetaW_start = 0.48);
@@ -65,6 +66,7 @@ private:
    double pizzt_MZ{0.};               ///< transverse Z self-energy at p^2 = MZ^2
    double piwwt_MW{0.};               ///< transverse W self-energy at p^2 = MW^2
    double piwwt_0{0.};                ///< transverse W self-energy at p^2 = 0
+   double mw_pole{0.};                ///< pole mass of W boson to be calculated from muon decay
 
    double calculate_rho_hat_tree() const;
    double calculate_delta_rho_hat(double) const;